From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D21CBC4167B for ; Thu, 30 Nov 2023 15:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346341AbjK3Phk (ORCPT ); Thu, 30 Nov 2023 10:37:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232180AbjK3Phh (ORCPT ); Thu, 30 Nov 2023 10:37:37 -0500 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95B7E10E4 for ; Thu, 30 Nov 2023 07:37:43 -0800 (PST) Received: by mail-io1-xd2c.google.com with SMTP id ca18e2360f4ac-7b37a2e6314so12837639f.1 for ; Thu, 30 Nov 2023 07:37:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1701358663; x=1701963463; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=eRo1oknj4mG3obwA0KmAvZPEjccwf277vmOJQMSbu+o=; b=V5HSyfWxih5vlN9sEwNh4WyJLxo2rNJRaDQed8gzXIOrjHWi07juEfASs39Vl364vr oieI9VpmVVFeMwXkwp6ggdI53xyuUSNHfsu+R4XLpL7E182oLXp1m7K6B3UhRN4TaZ8E nQjdDZgGWR7pe4NmRoBW3HIEoj2RK0vdskfSIz2A9CMWTJTJWDg0EpJRbw0RoKtXL05L mU9NhSuhajtyoObvym8TLDlsPOxUMOBxDAnncYmSOdQvIeUpxlzmNMammDN63SRSMg23 vTnF6GpOZpiR7ROey4cnLd3zxwYnrCtDUpJf4fC9ldzgumNEVV0wOJ/xdLtIxLRWbO3u xStg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701358663; x=1701963463; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=eRo1oknj4mG3obwA0KmAvZPEjccwf277vmOJQMSbu+o=; b=DCkqaoMqTGws+UAmNPJl7gNYp5CJxN6WeJWTFcSyAJdgWCvdn4v2jxfg8EmyC6QdN7 hTKnm5fdaTdC00MkNCJVWcT2J8HHMes77GsnCPSj/kd9Q+aX3O0vcwVsr3SFiWhzyTqh xlb0UwzOP9frScjRp4R8CAJgb4tDC9947bdKm7i6C7hDv8npBlK607vrDnk1nMY6q67L pD74OMkGvXsLZK4EBtLgJ+FA/Aw2ilvAsIl8q0oVdwknsa+pBFpr66CAFmwIcKx/aW+8 Nl60SOvty5Hm97ZcFqCaKICuKYYoji5v/VHfE+/wuuLXu4vUdBAhJ5ULZG9pBImVqbIg DU9A== X-Gm-Message-State: AOJu0Yx9ZU18Qb/9auWK6T2iK9cx8LXkG3HXCn6ezdPnTf+ybNr2tVv+ 31MUVw4j5EmRu0i9N/h86iW6SA== X-Google-Smtp-Source: AGHT+IGSYO+9xXxMk+Bn7bqLWNX6OK2f41ov3rtjgV/FWA2seq3P2qUsGUYmTrmQqmmsuPk1XL1ywQ== X-Received: by 2002:a05:6602:155:b0:7b3:6d5c:b8e with SMTP id v21-20020a056602015500b007b36d5c0b8emr2615464iot.0.1701358662939; Thu, 30 Nov 2023 07:37:42 -0800 (PST) Received: from [192.168.1.116] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id el4-20020a0566384d8400b00468590162f4sm345409jab.178.2023.11.30.07.37.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Nov 2023 07:37:42 -0800 (PST) Message-ID: Date: Thu, 30 Nov 2023 08:37:40 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] zram: Using GFP_ATOMIC instead of GFP_KERNEL to allocate bitmap memory in backing_dev_store Content-Language: en-US To: Dongyun Liu , minchan@kernel.org, senozhatsky@chromium.org Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, lincheng.yang@transsion.com, jiajun.ling@transsion.com, ldys2014@foxmail.com, Dongyun Liu References: <20231130152047.200169-1-dongyun.liu@transsion.com> From: Jens Axboe In-Reply-To: <20231130152047.200169-1-dongyun.liu@transsion.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/30/23 8:20 AM, Dongyun Liu wrote: > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index d77d3664ca08..ee6c22c50e09 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -514,7 +514,7 @@ static ssize_t backing_dev_store(struct device *dev, > > nr_pages = i_size_read(inode) >> PAGE_SHIFT; > bitmap_sz = BITS_TO_LONGS(nr_pages) * sizeof(long); > - bitmap = kvzalloc(bitmap_sz, GFP_KERNEL); > + bitmap = kmalloc(bitmap_sz, GFP_ATOMIC); > if (!bitmap) { > err = -ENOMEM; > goto out; Outside of this moving from a zeroed alloc to one that does not, the change looks woefully incomplete. Why does this allocation need to be GFP_ATOMIC, and: 1) file_name = kmalloc(PATH_MAX, GFP_KERNEL); does not 2) filp_open() -> getname_kernel() -> __getname() does not 3) filp_open() -> getname_kernel() does not 4) bdev_open_by_dev() does not IOW, you have a slew of GFP_KERNEL allocations in there, and you probably just patched the largest one. But the core issue remains. The whole handling of backing_dev_store() looks pretty broken. -- Jens Axboe